Display Basics

Abstract

A TFT is a type of LCD. An LCD is a display that uses liquid crystals. The crystals self-align into twists which reorient the polarization of light passed through them. An electrical field untwists them which changes the direction of polarization. Transistors are used to control the amount of twist and therefore the amount of light passed through. Each pixel on a display consists of a red, green, and blue sub-pixel. The level of light passing through each sub-pixel can be controlled individually resulting in a large combination of possible colors. There are several key attributes of an LCD display including resolution, brightness, contrast ratio, color depth, viewing angle, color gamut, and response time. There are several different hardware interfaces used for LCDs including parallel, SPI, I²C, LVDS, MIPI, and eDP.